Now, new research shows that blood pressure-lowering pills may help lower the risk of stroke in people with prehypertension.

More than 50 million Americans have mildly elevated blood pressure or prehypertension. It is defined as systolic blood pressure (the top number) between 120 and 139 or diastolic blood pressure (the lower number) between 80 and 89. High blood pressure is defined as 140/90 mm Hg or higher.

High blood pressure (hypertension) is major risk factor for stroke and heart disease. It is treated aggressively with lifestyle changes and medications. The American Heart Association encourages lifestyle changes, not drugs, for people with prehypertension. This includes losing weight (if necessary), eating a healthy, low-salt diet, exercising regularly, and quitting smoking.

Medication Lowers Stroke Risk

Adding blood pressure-lowering drugs to lifestyle changes may prevent more strokes in people with prehypertension, according to the new research.

Researchers reviewed 16 studies of more than 70,000 people with prehypertension who were treated with blood pressure medication or a placebo. Those who took blood pressure-lowering medications were 22% less likely to have a stroke, compared with those who did not. The findings appear in Stroke.

“If lifestyle changes do not fix your prehypertension, then [medication] can help reduce your blood pressure and your stroke risk," says researcher Ilke Sipahi, MD. Sipahi is an assistant professor of cardiovascular medicine at Case Western Reserve University in Cleveland, Ohio.

“We think that our findings need to be discussed extensively ... before a change in guidelines is implemented,” Sipahi says via email. “For the prehypertensive patient with additional risk factors for stroke, such as high cholesterol or smoking, [medication] can be very helpful to reduce the risk, especially if blood pressure levels do not normalize with lifestyle changes.”

Treat With Diet Changes First

Outside experts say there is not enough evidence to warrant a shift in the guidelines ... yet.